Recent developments in nanofluids indicate that the addition of nanoparticles to water-based drilling fluids can alleviate many drilling problems, including wellbore instability, lost circulation, torque and drag force, differential pipe sticking, shale swelling and low drilling rates. In this study, hydrophilic Gilsonite fine particles were produced by reaction of natural Gilsonite with a mixture of sulfuric acid and nitric acid followed by a planetary ball mill process. The hydrophilic Gilsonite was characterized using FTIR, XRD, FE-SEM, elementals analysis, thermogravimetric analysis and mass spectroscopy. All experiments showed that the characteristics of the hydrophilic Gilsonite, due to its surface modification, were different from those of natural Gilsonite. Also, Gilsonite nanoparticles were characterized by means of dynamic light scattering technique, FE-SEM, Fourier transform infrared spectroscopy, as well as thermogravimetric and differential thermogravimetric analysis. Hydrophilic Gilsonite nanoparticles were dispersed in water with an average diameter of 300 nm without adding any dispersant. The effects of hydrophilic Gilsonite nanoparticles on the rheological properties as well as the fluid loss of the water-based drilling mud were investigated before and after the hot-roll process. The results showed that simultaneous adding of 10 gr of hydrophilic Gilsonite nanoparticles to the base fluid and reducing the starch concentration to half of its initial value resulted into the best composition for efficient water-based drilling mud. Moreover, the addition of hydrophilic Gilsonite nanoparticles to water-based drilling mud was investigated, and its effects upon the well-cleaning process, rheological properties, filtration loss reduction, lubricity characteristics, and, more importantly, on the differential sticking and shale swelling of the base fluid (b2) were evaluated. Also, after the hot roll, the plastic viscosity improved, the yield point was remarkab